Laundry washing and washing/drying machines (hereinafter simply referred to as “washing machines”) are household appliances designed to wash laundry and typically comprise a washing tub housing a rotatable perforated drum in which the laundry to be washed can be loaded/unloaded.
In order to carry out washing operations on laundry loaded into the drum, washing liquid (e.g., water, water mixed with washing products and/or water mixed with rinsing products) is introduced—through an inlet line—in the washing tub of the washing machine during a washing liquid loading phase. Being the drum perforated, the washing liquid penetrates thereinto, soaking the laundry.
Then, a washing phase is started in which the drum is rotated, so that the laundry loaded into the drum is washed thanks to the chemical reactions exerted by the washing liquid, and to the mechanical action exerted by the tumbling action caused by the rotation of the drum.
At the end of the washing phase, the washing liquid (which is at this point mixed with dirt particles removed from the laundry) is drained from the washing tub for allowing the carrying out of rinsing and/or spin-drying operations on the laundry.
For this purpose, the washing machine is provided with a discharge system adapted to selectively drain the washing liquid from the washing tub. The discharge system comprises a discharge duct for receiving washing liquid from the washing tub. For this purpose, the discharge duct is fluidly coupled with the washing tub through a discharge hole provided at the bottom of the washing tub. A drain pump, usually positioned downstream the discharge duct, is operable to cause the washing liquid located into the discharge duct to be discharged through a drain hose adapted to be connected to the water drain network system.
Some known washing machines are also provided with a recirculation system which, during the washing liquid loading phase and/or washing phase and/or rinsing phase, takes some liquid from the bottom of the tub (typically via the discharge duct), and reintroduces this liquid into a different region of the washing tub, or directly into the drum, so as to deliver the liquid to the laundry from more than one directions, and not only from the bottom of the tub; this allows a better wetting of the laundry, and therefore using a smaller amount of liquid during the above mentioned phase(s).
According to a solution known in the art, the recirculation system comprises a recirculation conduit fluidly coupled with the discharge duct and a recirculation pump, usually positioned downstream the discharge duct in parallel with the drain pump, which is operable to cause the washing liquid located into the discharge duct to be reintroduced into the washing tub through the recirculation conduit. The recirculation conduit feeds one or more nozzles arranged to spray the recirculated washing liquid into the washing tub, for example directly inside the drum.
According to this solution, when the recirculation pump is active and the drain pump is off, washing liquid is taken from the discharge duct and sprayed back into the drum; when the recirculation pump is off and the drain pump is active, washing liquid located in the discharge duct is instead discharged through the drain hose. This solution is quite expensive, since it provides for two dedicated pumps, i.e., the drain pump and the recirculation pump. Moreover, since such two pumps have to be installed in parallel with each other downstream the discharge duct, the installation thereof is quite time consuming and it also disadvantageously reduces the space available in the washing machine for housing other hydraulic, mechanic and/or electric apparatuses of the washing machine.